1. Technical Field
The present invention relates to signal processing, and more particularly to throughput enhancement through repercussive coding in multiple-input, multiple-output (MIMO) systems.
2. Description of the Related Art
In multiple user communication systems, the quality of the channel state information at the transmitter is very important to performing closed loop operation. Unlike single user systems where the quality of the channel estimate only effects the coding gain and not the scaling with the Signal-To-Noise Ratio (SNR), in multiple user systems the system performance would be quite limited if the channel state information is not precise.
There are two types of imprecision in the knowledge of the channel state. One type of imprecision is the channel estimation error and the other type of imprecision is the delay in this information due to the causality of the system. It turns out that in a system which can have quite good channel estimation, the latter problem with the delay still causes unrecoverable error and severely limited performance if proper coding is not used.